Siemens SINUMERIK 840D sl Function Manual page 327

Program code
N170 ENDIF
N180 IF ($AA_IW[X] > 10)
N190
N200 ENDIF
N210 IF ( (R1+R2) = 1 )
N220
N230 ENDIF
N240 M30
N120: if G70 is replaced by G700, alarm 61000 (N220) does not occur.
Synchronized actions
To ensure, in the case of synchronized actions, that the current part program context does not
determine the system of units used in the condition and/or action part, the system of units must
be defined within the synchronized action (condition and/or action parts). This is the only way
of achieving defined, reproducible behavior in the use of length-related data within a
synchronized action.
Example 1
The system of units is not specified within the synchronized action. The X axis is therefore
traversed in the system of units of the parameterized initial setting:
Program code
N100 R1=0
N110 G0 X0 Z0
N120 WAITP(X)
N130 ID=1 WHENEVER $R1==1 DO POS[X]=10
N140 R1=1
N150 G71 Z10 F10
N160 G70 Z10 F10
N170 G71 Z10 F10
N180 M30
Example 2
The "metric" system of units is explicitly programmed with G71 within the synchronized action.
This means the traversing motion of the X axis takes place in the metric measuring system:
Program code
N100 R1=0
N110 G0 X0 Z0
N120 WAITP(X)
N130 ID=1 WHENEVER $R1==1 DO G71 POS[X]=10
N140 R1=1
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
G2: Velocities, setpoint / actual value systems, closed-loop control
R2=1
SETAL(61000)
7.3 Metric/inch measuring system
Comment
; [mm] (basic system) > 10 [inch]
; (programmed system of units)
; Alarm if only one of the two
; conditions (N150, N180) is TRUE
Comment
; X = 10 inch or mm, depending on the
; rest of the part program
; Z = 10 mm, X = 10 mm
; Z = 10 inch, X = 10 inch
; Z = 10 mm, X = 10 mm
Comment
; X = 10 mm, independent of the
; rest of the part program
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